Building Science. Intro Dr John Straube, P.Eng. Principal, RDH Building Science Assoc. Professor, University of Waterloo Waterloo, Canada

Transcription

1 Dr John Straube, P.Eng. Principal, RDH Building Science Assoc. Professor, University of Waterloo Waterloo, Canada Building Science Intro à Building Science à Changes and Future Trends à Three topics à ci à Prefabrication à Housing Types à Tall Wood Case Study 2 of 1

2 Changes and Trends à Changing projects à Retrofit à Changing / Aging population à Infill + In-law units, granny flats, etc à Mid-rise, especially urban Wood 5, 6 storey + à Multi-use à Regional variations (labor vs land price) Vermont vs Boston vs Kansas vs Seattle 3 of Changes and Trends à Changing needs à Lower energy à More comfort à Better IAQ à Faster construction à Weather insensitivity à Higher Labor efficiency 4 of 2

3 Changing Demands à More insulation à Quality inspection à Less thermal bridging à More airtightness à Blower door testing à Changing techniques à Save labor à Reliably & provably deliver airtightness and thermal bridge reductions 5 of Innovation à The industry is slow to change and conservative à Of course it is, it should be à Buildings are long term à Buildings are massive investment à Innovation is NOT something new, it is something better 6 of 69 3

4 Innovation à Technology is improving à Mostly limited by demand from market place à Triple, quad glazing, Water barriers à Price is dropping à Photovoltaics super cheap à LED lights the norm à Ductless mini-splits à Insulation is cheap and relatively less $ 7 of Needed Innovation à Many mechanical system changes à More heatpump solutions à Central heat systems with scop >2.0 at < 0F à Domestic hotwater solutions à Becoming largest load heat pumps not great at 120F water! à Balanced Ventilation with exhaust appliances à The price of super airtightness à We don t really need our furnace or fridge connected to the internet 8 of 69 4

5 Smaller furnaces à Smaller, more efficient and multifamily buildings need smaller furnances! à Long run times à Steady heat à Smaller ducts à Poor industry engagement Dettson Chinook furnace 15KBtu/hr 9 of Future à More quality assurance and control à E.g., Blower door, infra red scans à More Prefabrication à Attack labor cost, reliability, weather à Net Zero Energy Buildings, happening but à Only small % of total use à need to rework grid. à Existing buildings and retrofit à Massive current & future energy users à Need comfort, IAQ upgrades 10 of 69 5

6 Continuous Insulation 11 of Getting to Higher R-values Base 2x6 Framed Wall <R-16 (wood) Issues: cladding attachment, thickness Split Insulation R-20 to R-60+ Exterior Insulation R-15 to R-60+ Issues: thermal bridging, thickness, durability Interior Insulation R-20 to R-30+ Deep Stud, Double Stud, SIPS R-20 R-80+ Issues: cladding attachment, material selection Issues: thickness, durability, 12 interior of 69 details 6

7 R-10 to R-19 Interior air-vapor barrier Standard for over 60 years 13 of From: R-13 to R-40+ Exterior air barrier Used for over 30 years 14 of From: 7

8 R-20 to R of From: R-20 to R-40+ Exterior air barrier 16 of 8

9 Exterior Insulation ( ci ) à Research and experience have shown it works à But knowledge not well disseminated à Uncertainty in practise (not reality) à Vapor control à Wetting and drying à Cladding attachment 17 of Field research / demo à 3 stone wool 2.5 XPS 2 PIC ccspf 2x6 I- joist Dbl stud of 9

10 Test Wall R-values à 2x8 with ccspf only R24 à Others reduce heat flow by half of Code à Walls 5 & 6 have no 6 mil poly of OSB Sheathing MC North wall, airtight Moisture Content (M%) Double stud/ I-joist N1-OSB M N2-OSB M N3-OSB M N5-OSB M N6-OSB M N7-OSB M PIC/XPS no poly 5 Sep Nov Jan Mar May Jul Stonewool 20 of 10

11 Add Calibrated Air leak of Air Leakage Moisture Content (M%) Start air injection 30 Double stud/ I-joist polyiso Possible Condensation Stop Air Injection Datum Ext Insul. N1-OSB L N2-OSB L N3-OSB L N5-OSB L N6-OSB L N7-OSB L 5 Jan Feb Mar Apr May of

12 North, I-joist Wall (5 yrs) Samples taken near MC Sensor for mold testing 23 of North, 2 PIC, FG, no poly 24 of 12

13 Prefab / Off-site à Panelized à Modular à Component 25 of Prefab and Modular Penn State RBDCC Brochure 26 of 13

14 Prefab à Promises à Improve labor efficiency, quality à Reduce weather sensitivity à Reduce cost à Challenges à Joints à Dimensional Control à Transport / Erection Moisture 27 of Offsite construction à We have long done this à E.g., Windows, stairs, boilers, millwork à Now, more, larger, lower value components à Panelized walls à Modular units 28 of 14

15 29 of Panel / Site Process à Panels & exterior exposed to weather à Cant do much interior work or MEP 30 of 30 15

16 31 of 69 Modular Process à Only exteriors exposed to weather, lots of interior work and MEP can be done à You are shipping air, and redundant ceiling 32 of 16

17 Modular.. And when does it make sense à Modular is ideal for: à à à Repetitive unit (modules) Remote locations - labour Locations where construction is disruptive inner city à Modular may not be ideal for: à à Open floor layouts such as office spaces Complex floor plans More $ allows modular everywhere. 33 of 34 of 17

18 35 of Expecting? Or is the tarp leaking? 36 of 18

19 Temporary roof, weighted to limit blowing off Ponding feature is free 37 of Rain damage and mold 38 of 19

20 Toffino, BC lifting Manage moisture from factory yard to close in on site 39 of Your module has landed now what 40 of 20

21 Water resistant side walls Construction protected windows PassiveHouse prefab BellaBella 41 of Types of Housing Future growth will be in à Multi-unit à Retrofit à ADU of 21

22 Multi-unit residential à Land use, walkable cities, aging population etc demand more multi-unit (not multifamily) 43 of Fire and sound separation à High Density / Mixed-use means à Better separation à New techniques of compartmentalization à Construction sequencing à Quality control 44 of 22

23 Renovation & Retrofit 45 of Retrofits à Huge existing stock of buildings, means: à Energy-efficient retrofits must be part of any solution à Approach varies more than new construction à Can we just exterior retrofit like siding? 46 of 23

24 Changing things à Changes things à New windows, new furnace, added insulation à Increased airtightness à Different temperatures à Approach à Add airtightness (add mechanical ventilation) à Add exterior insulation (improve rain control) 47 of Accessory Dwelling Units Zoning & State laws changes Provides affordable housing and reflects changing demographics From: From: modularlifestyles.com 48 of 69 24

25 Tall Wood à The resurgence of wood in tall and large buildings 49 of Mass/Heavy Timber Engineered Materials à Taller structures require heavier timber & engineered lumber components à à à à à à Cross Laminated Timber (CLT) Nail Laminated Timber (NLT) Glulam Laminated Strand Lumber (LSL) Parallel Strand Lumber (PSL) Laminated Veneer Lumber (LVL) à Many tall wood structures will also incorporate steel and concrete NLT CLT 50 of 69 25

26 New Tall Wood Montreal Multifamily CLT 51 of 69 New Tall Wood Minneapolis Office Building NLT 52 of 69 26

27 Some Potential Risks and Challenges with Mass Timber 53 of 69 Case Study - UBC Dorms à 18 storey, tall wood à CLT, Glulam à Enclosure fabricated offsite 54 of 69 27

28 Structural System:Wood+Concrete 55 of 69 Structural System Concrete Core à 56 of 69 28

29 Structural System Glulam Columns 57 of 69 Structural System CLT Floors 58 of 69 29

30 Concrete, Steel and Wood -Hybrid Structure 59 of 69 Wall Panelization & Window Installation in Factory 60 of 69 30

31 Wall Panelization & Window Installation in Factory 61 of 69 Site Installation Perimeter Angle 62 of 69 31

32 Site Installation Panel Hoisting 63 of 69 Sealing joints 64 of 69 32

33 Sealing Joints 65 of 69 Note open steel stud frame Services and seamless finish now installed 66 of 69 33

34 Exterior near completion 67 of 69 In closing à Many new changes and demands à Need to change what we do à Housing forms à Higher expectations à More reliably delivered à Build on our knowledge and experience, not reinvent à But much of industry still needs to learn a lot about building science à Need to train next generation 68 of 69 34

35 Thank you JOHN STRAUBE à rdh.com buildingsciencelabs.com Building Science 69 of 69 35